Rodent models of diabetes and its complications have and v\/ill continue to provide fundamental insights into the molecular basis of human metabolic disease. The investigators of the Columbia DRC employ more than one hundred murine models to study diabetes and its complications. Characterizing the phenotype of these animals in an efficient, effective and timely fashion is critical for the productive study of diabetes at Columbia. The Mouse Phenotyping Core (MPC) has been in great demand during the current funding cycle and has evolved significantly since the last submission to meet the needs of DRC investigators. The MPC has proven broadly successful in achieving its mission of assisting individual investigators in characterizing metabolic phenotypes of mice, fulfilling more than 23,000 service requests for 17 DRC members supported by 42 grants, and for 11 non-DRC members. The Core has been instrumental in obtaining 11 new grants, and in 60 publications (32 as primary Core). The Mouse Phenotyping Core currently provides services that facilitate the efficient characterization of mouse models of diabetes and its complications: Body Composition Analysis, Whole Body Metabolic Assessment and Multiplex Protein Assays. The MPC services complement those provided by other DRC Cores, so that investigators who take advantage of DRC resources can fully characterize mice with genetic, histologic, immunologic and metabolic analyses. The Core has been built through the strong support ofthe Naomi Berrie Diabetes Center and Columbia University. To continue effectively serving the needs ofthe Columbia diabetes research community, the Mouse Phenotyping Core has evolved by adding and expanding services. In response to investigator surveys and as proposed in our last competing renewal, we developed two phenotyping services during the current funding period: Whole Body Metabolic Assessment and Lipidomics. These services are now well established and indeed have been in such high demand and so successful that they have each undergone one round of expansion. In response to a more recent set of DRC surveys and investigator requests, we have completed the expansion of the Metabolic Clamp Assessment. Projections indicate that demand for these Core services will remain high, should we be refunded.